[qtmultimedia] Add restriction feature ffmpeg does not support Linux

[jimwang118]

Fixes #36429

ffmpeg requires libva to build on Linux, but currently there is no such port in vcpkg, so the build fails. Therefore add the restriction that ffmpeg does not support building on Linux.

• Changes comply with the maintainer guide.
• SHA512s are updated for each updated download.
• The "supports" clause reflects platforms that may be fixed by this new version.
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

This feature passed with following triplets:

x64-windows
x64-linux

[Neumann-A]

ffmpeg requires libva to build on Linux, but currently there is no such port in vcpkg, so the build fails. Therefore add the restriction that ffmpeg does not support building on Linux

that just means libva needs to be system provided for now. That does not rectify using supports!

[jimwang118]

that just means libva needs to be system provided for now. That does not rectify using supports!

Does this mean that I need to tell the user that he needs to install libva manually before installing feature ffmpeg?

[dg0yt]

... similar to all the x packages ...